Political beliefs have been shown to spillover into non-political domains, such as consumer spending, choice of romantic partner, and job-hiring. My research investigates how political beliefs affect professional judgements in a setting with profound consequences for public health. Physicians frequently interact with patients about politically salient health issues, such as drug use, firearm safety, and sexual behavior. We investigate whether physicians’ own political views affect their treatment decisions on these issues. We linked the records of over 20,000 primary care physicians in 29 US states to a voter registration database, obtaining the physicians’ political party affiliations. We then surveyed a sample of Democratic and Republican primary care physicians. Respondents evaluated 9 patient vignettes, 3 of which addressed especially politicized health issues (marijuana, abortion, firearm storage). Physicians rated the seriousness of the issue presented in each vignette and their likelihood of engaging in specific management options. On the politicized health issues – and only on such issues – Democratic and Republican physicians differed substantially in their expressed concern and their recommended treatment plan. We control for physician demographics, like age, gender, and religiosity, patient population, and geography. Physician partisan bias can lead to unwarranted variation in patient care. Awareness of how a physician’s political attitudes might affect patient care is important to physicians and patients alike.